"Black carpet beetle The black carpet beetle (""Attagenus unicolor"") is a beetle that can be a serious household pest. The larvae grow to in length, are reddish brown in colour and covered with bristles. The larval form feeds on natural fibres, damaging carpets, furniture and clothing. ""Attagenus unicolor"" undergoes complete metamorphosis, which has four life stages: Egg, larvae, pupae and adult. Each stage looks different, and needs different amounts of time to reach the next stage. Eggs are usually laid near or on a food source. If no food source can be found, the female will lay them in dark"
"continues to develop and lay eggs; in the typical case of ""Psoroptes"", females produce one large egg at a time. In most parasitic mites, the entire lifecycle takes place on the host, with all stages present simultaneously (an exception is the trombiculid mites where the nymphs and adults are free-living). This type of lifecycle, with all active stages resembling each other in structure and feeding mechanism, is called incomplete metamorphosis (or hemimetabolism). A metamorphosis is a distinct change of body shape. When the larval stages of an invertebrate animal are completely different from the adult stage, as with caterpillars changing"
"incubation period, molting from first to second (and possibly third) stage larva takes place within the egg. In most adult dogs, cats and foxes, the full lifecycle does not occur, but instead second stage larvae encyst after a period of migration through the body. Reactivation of the larvae is common only in pregnant or lactating cats, dogs and foxes. The full lifecycle usually only occurs in these females and their offspring. Second stage larvae will also hatch in the small intestine of an accidental host, such as a human, after ingestion of infective eggs. The larvae will then migrate through"
"Larva A larva (plural: ""larvae"" ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form (""e.g."" caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae are frequently adapted to environments separate from adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water"
"The egg has a tough spiny coat, and usually hatches to release a free-swimming trochophore larva, typical of many other mollusc groups. In a few cases, the trochophore remains within the egg (and is then called lecithotrophic – deriving nutrition from yolk), which hatches to produce a miniature adult. Unlike most other molluscs, there is no intermediate stage, or veliger, between the trochophore and the adult. Instead, a segmented shell gland forms on one side of the larva, and a foot forms on the opposite side. When the larva is ready to become an adult, the body elongates, and the"
"undergo complete metamorphosis. The larvae are commonly called caterpillars, and are completely different from their adult moth or butterfly forms, having a cylindrical body with a well-developed head, mandible mouth parts, three pairs of thoracic legs and from none up to five pairs of prolegs. As they grow, these larvae change in appearance, going through a series of stages called instars. Once fully matured, the larva develops into a pupa. A few butterflies and many moth species spin a silk case or cocoon prior to pupating, while others do not, instead going underground. A butterfly pupa, called a chrysalis, has"
"stage to avoid extreme conditions, in which case this stage can last several months. The eggs of some types of insects, such as tsetse flies, or aphids (which are hemimetabolous), which hatch before they are laid. The second stage of the holometabolous life cycle is the larva (plural: larvae). Many adult insects lay their eggs directly onto a food source so the larvae may begin eating as soon as they hatch. Larvae never possess wings or wing buds, and have simple rather than compound eyes. In most species, the larval stage is mobile and worm-like in form. Larvae can be"
"stage between larvae and adult. In 1883, John Lubbock revitalized Harvey's hypothesis and argued that the origin and evolution of holometabolan development can be explained by the precocious eclosion of the embryo. Hemimetabolan species, whose larvae look like the adult, have an embryo that completes all developmental stages (namely: ""protopod"", ""polipod"", and ""oligopod"" stages) inside the eggshell. Holometabolan species instead have vermiform larvae and a pupal stage after incomplete development and hatching. The debate continued through the twentieth century, with some authors (like Charles Pérez in 1902) claiming the precocious eclosion theory outlandish, Antonio Berlese reestablishing it as the leading"
"(i.e. legs are not included) Comparison of Engorged ticks Larval, nymph and adult (female) stages. The adult male tick does not engorge. The larvae and nymphs are neither male nor female. Only the final adult stage of ""Ixodes holocyclus"" shows obvious sex variation. Larvae are neither male nor female. Nymphs are sexually immature (have no genital aperture). The male does not engorge. The shield (""scutum"") covers the entire dorsal body. It has a tortoiseshell pattern. The mouthparts section (the ""capitulum"") is very short because it is not required for feeding from the host (though it may be used to feed"
"its definitive host where it can mature into an adult. The life cycle of nematomorphs has 4 stages: First is the egg, which takes about 10–12 days to complete its larval development after being laid. Second is the pre-parasitic larva that hatches from the egg; the fully developed larva remains in the egg 7–10 days before hatching. Third is the parasitic larva that develops within an invertebrate host; larvae swim about freely in the water after hatching, and are ingested with water when insects drink. If the larvae does not find a host within a few days, they will die."
"through a dramatic reorganization when transitioning from aquatic larvae to terrestrial adults, while others, such as the Axolotl, display paedomorphosis and never develop into terrestrial adults. Within the genus ""Ambystoma"", species have evolved to be paedomorphic several times, and paedomorphosis and complete development which can both occur in some species. In newts, there is no true metamorphosis because newt larvae already feed as predators and continue doing so as adults. Newts' gills are never covered by a gill sac and will be resorbed only just before the animal leaves the water. Just as in tadpoles, their lungs are functional early,"
"given time. This is supported by the fact that there is only one female with significantly larger ovaries over the other females at any given time and this select female is considered the primary egg layer. The biology/anatomy of the larva has unique characteristics (associated only with ""Microstigmus"") that reveal evolutionary features. One is the conical supranal process which is potentially an adaptation for obtaining the prey provisions stuck on the walls of a nursery cell. During the larval stage, there also is a complete lack of spinnerets which indicate that a pupal stage with a cocoon is not present"
"pre-larva or pre-zoea. Through a series of moults, the young animal then passes through various zoea stages, followed by a megalopa or post-larva. This is followed by metamorphosis into an immature form, which broadly resembles the adult, and after further moults, the adult form is finally reached. Some crustaceans continue to moult as adults, while for others, the development of gonads signals the final moult. Any organs which are absent from the adults do not generally appear in the larvae, although there are a few exceptions, such as the vestige of the fourth pereiopod in the larvae of ""Lucifer"", and"
"development stages: egg, larva, pupa and adult. Adults usually lay eggs on the underside of leaves or stems, and to a lesser extent on fruits. After hatching, young larvae penetrate leaves, aerial fruits (like tomato) or stems, on which they feed and develop.Pupae (length: 5–6 mm) are cylindrical in shape and greenish when just formed becoming darker in colour as they are near adult emergence. Adults are 6–7 mm in length and present filiform antennae and silver to grey scales . Black spots are present on anterior wings, and the females are wider and more voluminous than the males. The"
"have internal rudiments that emerge as adult legs at the final ecdysis). Examples include the maggots of flies or grubs of weevils. In contrast, the larvae of other Coleoptera, such as the Scarabaeidae and Dytiscidae have thoracic legs, but no prolegs. Some insects that exhibit hypermetamorphosis begin their metamorphosis as planidia, specialised, active, legged larvae, but they end their larval stage as legless maggots, for example the Acroceridae. Among the Exopterygota the legs of larvae tend to resemble those of the adults in general, except in adaptations to their respective modes of life. For example, the legs of most immature"
"""E. elvina"" are holometabolous and have four distinct development stages: egg, larva, pupa and adult. It takes a total of 45 days for an adult to eclose from an egg. The females lay the eggs on the upper surface of leaves, leaf petioles, or on the inflorescence of neotropical plants such as ""Calathea ovandensis"". The eggs are not laid in a clutch, but are generally isolated. Sometimes, however, they may be found in widely spaced groups of five or fewer eggs. It takes, on average, 3 days for the first instar of larva to hatch out of the egg. The"
"are much less efficient, spending more time and getting less food to the larvae. The larvae of some species (for example, some newts) can become pubescent and do not develop further into the adult form. This is a type of neoteny. It is a misunderstanding that the larval form always reflects the group's evolutionary history. This could be the case, but often the larval stage has evolved secondarily, as in insects. In these cases the larval form may differ more than the adult form from the group's common origin. Within Insects, only Endopterygotes show different types of larvae. Several classifications"
"fully mature and their development and growth stops. Their juveniles are larvae or nymphs. In vertebrates and some invertebrates (e.g. spiders), larval forms (e.g. tadpoles) are usually considered a development stage of their own, and ""juvenile"" refers to a post-larval stage that is not fully grown and not sexually mature. In amniotes and most plants, the embryo represents the larval stage. Here, a ""juvenile"" is an individual in the time between hatching/birth/germination and reaching maturity. Juvenile (organism) A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles sometimes look very different"
"stage larvae in the intestines of the cat, dog or fox host (for consistency, this article will assume that second stage larvae emerge from ""Toxocara"" eggs, although there is debate as to whether larvae are truly in their second or third stage of development). Larvae enter the bloodstream and migrate to the lungs, where they are coughed up and swallowed. The larvae mature into adults within the small intestine of a cat, dog or fox, where mating and egg laying occurs. Eggs are passed in the feces and only become infective after several weeks outside of a host. During this"
"have been suggested by many entomologists, and following classification is based on Antonio Berlese classification in 1913. There are four main types of endopterygote larvae types: Larva A larva (plural: ""larvae"" ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form (""e.g."" caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae"
"in other hemipterans, tessaratomids are hemimetabolic, undergoing incomplete metamorphosis. This means that they do not possess larval and pupal stages. Instead, juvenile tessaratomids (called nymphs), hatch directly from the eggs. The nymphs resemble fully grown adults except for size and the absence of wings. Nymphs usually undergo four to five successive stages of moltings (ecdysis), increasing in size and becoming more adult-like with each stage until the final molting. The stages are individually known as instars, with the earliest stage (just after hatching) being known as the first nymphal instar. Nymphs may also differ significantly from adults in colors and"
"and the small microlecithal eggs do not allow full development. Instead, the eggs hatch into larvae, which may be markedly different from the adult animal. In placental mammals, where the embryo is nourished by the mother throughout the whole fetal period, the egg is reduced in size to essentially a naked egg cell. Mesolecithal eggs have comparatively more yolk than the microlecithal eggs. The yolk is concentrated in one part of the egg (the ""vegetal pole""), with the cell nucleus and most of the cytoplasm in the other (the ""animal pole""). The cell cleavage is uneven, and mainly concentrated in"
"subsequent few months, the larvae undergo metamorphosis, during which they develop legs, and the gills are absorbed and replaced by air-breathing lungs. Some species, such as the North American newts, also become more brightly coloured during this phase. Once fully metamorphosised, they leave the water and live a terrestrial life, when they are known as ""efts"". Only when the eft reaches adulthood will the North American species return to live in water, rarely venturing back onto the land. Conversely, most European species live their adult lives on land and only visit water to breed. Many newts produce toxins in their"
"species hatch directly into the adult form, many have a trochophore larva, which metamorphoses into the adult after anything from a day to a month, depending on species. In a few species, the trochophore does not develop directly into the adult, but into an intermediate ""pelagosphaera"" stage, that possesses a greatly enlarged metatroch (ciliated band). Metamorphosis occurs only in the presence of suitable sediment, and is triggered by the presence of adults. The phylogenetic placement of this phylum in the past has proved troublesome. Originally classified as annelids, despite the complete lack of segmentation, bristles and other annelid characters, the"
"for all roaches, individuals undergo hemimetabolous metamorphosis, which means the change from juvenile to adult is gradual. The three distinct stages in their lifecycle are egg, nymph, and adult. Only adults are able to reproduce and have wings. Prolonged nymphal stages, along with additional molts, can sometimes occur in ""B. giganteus"" for a number of reasons. One hypothesis is that the absence jostling and mutual stimulation which are found often in colony life could slow the developmental process. In other instances, lower temperatures and reduced humidity can lead to delayed maturation and an increase in the number of molts. This"
"morphological differences between adults and larvae. Metamorphosis was likely lost in stereospondyls because extreme phenotypic plasticity allowed environmental acclimation through changes in morphology without needing a binary developmental life history with larval and adult stages. This eventually led to neoteny whereby the larval stage is morphologically very similar to the adult stage. Stereospondyls including ""Rhineceps"" only had gradual changes between juvenile and adult stages, and their fossils do not suggest the presence of any type of metamorphosis, major or minor. Greater ambiguity is created because stereospondyls including ""Rhineceps"" have traits traditionally associated with metamorphosis, including amphibious dermal pitting. The presence"
"a complete metamorphosis. The females lay eggs with high selectivity on their special hosts and at specific sites there. For example, eggs laid on the legs of horses in the case of species of ""Gasterophilus"". The horse licks at the irritated skin and the larvae transfer to the mouth of horse. The larvae penetrate tissues in the oral cavity, feed parasitically whilst migrating through tissue of the esophagus to finally reach the stomach. The final larval stage is completed with the larvae attached to the mucosa of the horse's stomach. When ready to pupate the larvae detach and are voided"
"developed in about one month after being laid and then enters diapause to overwinter. The egg is in the overwintering stage lasting for eight or nine months. Development ceases in preparation for the winter. After an acclimation stage, during which the larva inside the egg reduces its water content, eggs can withstand freezing temperatures. The larva inside the egg resumes activity in the spring, and reabsorbs water. The larva will then chew through the chorion of the egg and the protective hair of the egg cluster in the spring. Egg clusters are usually an oval about of an inch wide"
"one-eyed larva comprising a head and a telson, without a thorax or abdomen. This undergoes six months of growth, passing through five instars, before transforming into the cyprid stage. Nauplii are typically initially brooded by the parent, and released after the first moult as larvae that swim freely using setae. The cyprid larva is the last larval stage before adulthood. It is not a feeding stage; its role is to find a suitable place to settle, since the adults are sessile. The cyprid stage lasts from days to weeks. It explores potential surfaces with modified antennules; once it has found"
"types: obtect, exarate, and coarctate. Obtect pupae are compact, with the legs and other appendages enclosed, such as a butterfly chrysalis. Exarate pupae have their legs and other appendages free and extended. Coarctate pupae develop inside the larval skin. The final stage of holometabolous insect development is the adult, or imago. Most adult insects have wings (excepting where secondarily lost) and functioning reproductive organs. Most adult insects grow very little after eclosion from the pupa. Some adult insects do not feed at all, and focus entirely on mating and reproduction. Around 45% to 60% of all known living species are"
"be totally different from older phases, such as the nauplius larvae of crustaceans, the nymphs of say, the Odonata, or the larvae of Endopterygota, such as maggots of flies. Such larval stages commonly have ecological and life cycle roles totally different from those of the mature animals. Secondly, often a major injury in one phase, such as the loss of a leg from an insect nymph, or a claw from a young crab, can be repaired after one or two stages of ecdysis. Similarly, delicate parts that need periodic replacement, such as the outer surfaces of the eye lenses of"
"(lecithotrophy). In species with normal development, eggs are roughly 1% of the size of the adult; in species with abbreviated development, and therefore more yolk in the eggs, the eggs may reach 1/9 of the adult's size. The post-larva of shrimp is called ""parva"", after the species ""Acanthephyra parva"" described by Henri Coutière, but which was later recognised as the larva of ""Acanthephyra purpurea"". In the marine lobsters, there are three larval stages, all similar in appearance. Freshwater crayfish embryos differ from those of other crustaceans in having 40 ectoteloblast cells, rather than around 19. The larvae show abbreviated development,"
"do not feed, and become inactive. To enter the third stage of homometabolous development, the larva undergoes metamorphosis into a pupa. The pupa is a quiescent, non-feeding developmental stage. Most pupae move very little, however, the pupae of some species, such as mosquitoes, are mobile. In preparation for pupation, the larvae of many species seek protected sites or construct a protective cocoon of silk or other material, such as its own accumulated feces. Some insects undergo diapause as pupa. In this stage, the insect's physiology and functional structure, both internal and external, change drastically. Pupae can be classified into three"